Higgins G A, Hoffman G E, Wray S, Schwaber J S
J Comp Neurol. 1984 Jun 20;226(2):155-64. doi: 10.1002/cne.902260202.
We have examined the distribution of neurotensin immunoreactivity within subnuclear regions of the nucleus of the tractus solitarius (NTS) and the dorsal motor nucleus of the vagus nerve (DVN) in the rat. In order to determine which regions of the NTS were involved in the regulation of baroreceptor reflexes, we mapped the central distribution of the aortic branch of the vagus nerve using transganglionic transport of horseradish peroxidase. Comparison of the pattern of aortic nerve innervation with that of the distribution of neurotensin-immunoreactive cells and fibers shows the dorsomedial nucleus of the NTS both to be the primary site of aortic baroreceptor termination and to contain the highest concentration of neurotensin-immunoreactive elements within the NTS. Neurotensin-immunoreactive fibers are also present in medial regions of the NTS adjacent to the area postrema where they may be involved in the modulation of vagal gastric afferents. Double-label experiments, in which, on the same tissue sections, neurotensin immunohistochemistry was combined with retrograde horseradish peroxidase labeling of DVN neurons, reveal a topographic innervation of vagal preganglionic motoneurons by neurotensin-immunoreactive fibers. The heaviest innervation is of lateral portions of the DVN and adjacent ventral portions of the NTS at the level of the obex, an area which may contain cardiac motoneurons. In this region neurotensin-immunoreactive fibers can be observed in close proximity to retrogradely labeled cells. The concentration of neurotensin elements in a region of the NTS which is involved in the control of baroreceptor reflexes provides a morphological basis for the cardiovascular effects produced by central administration of the peptide. Additional control may be exerted at the level of the motoneuron, as evidenced by apparent neurotensin fiber innervation of presumptive cardiac preganglionic neurons. Similarly, the distribution of neurotensin fibers suggests that the peptide may be acting in gastric regulatory areas of the NTS or on vagal secretomotor neurons to regulate gastric acid secretion.
我们研究了大鼠孤束核（NTS）和迷走神经背运动核（DVN）亚核区域内神经降压素免疫反应性的分布。为了确定NTS的哪些区域参与压力感受器反射的调节，我们利用辣根过氧化物酶的跨神经节运输绘制了迷走神经主动脉分支的中枢分布。将主动脉神经支配模式与神经降压素免疫反应性细胞和纤维的分布模式进行比较，结果显示NTS的背内侧核既是主动脉压力感受器终末的主要部位，也是NTS内神经降压素免疫反应性成分浓度最高的部位。神经降压素免疫反应性纤维也存在于NTS与最后区相邻的内侧区域，它们可能参与迷走神经胃传入纤维的调节。在同一组织切片上，将神经降压素免疫组织化学与DVN神经元的逆行辣根过氧化物酶标记相结合的双重标记实验显示，神经降压素免疫反应性纤维对迷走神经节前运动神经元有拓扑性支配。支配最密集的是DVN的外侧部分以及闩平面处NTS相邻的腹侧部分，该区域可能含有心脏运动神经元。在这个区域，可以观察到神经降压素免疫反应性纤维紧邻逆行标记的细胞。NTS中参与压力感受器反射控制的区域内神经降压素成分的浓度为该肽中枢给药所产生的心血管效应提供了形态学基础。如推测的心脏节前神经元明显的神经降压素纤维支配所证明的，在运动神经元水平可能还存在额外的调控。同样，神经降压素纤维的分布表明，该肽可能在NTS的胃调节区域或迷走神经分泌运动神经元上起作用，以调节胃酸分泌。
